Vehicle navigation systems typically use a satellite based location system to determine the location of the vehicle. Such systems have known drawbacks regarding locations where satellite signals are unavailable or weak.
Image based localization has been proposed as another method of determining a location of a vehicle. Previous image based localization techniques for vehicles have used inverse perspective mapping (IPM) to transform a camera image from a vehicle mounted camera into a top down image or bird's eye view image. The top down image may then be compared to known lane markings to determine the location of the vehicle.
IPM based localization techniques may have drawbacks because the IPM relies on known or assumed characteristics. For example, IPM techniques assume that the road is flat and that the camera pitch and yaw are known. These assumptions may not hold up in real world driving conditions. Further, the IPM image may only be compared to planar features (e.g., lane markings), which may not always be available or sufficient.